Antenna array



Aug. l5, 1933.

J. s. STONE 1,922,116

ANTENNA ARRAY 2 Sheets-Sheet 1 Filed April 12, 1950 WL A ToRNEY J. S. STONE ANTENNA ARRAY Aug. l5, 1933.

Filed April l2, 1930 2 Sheets-Sheet 2 I@ w 5 Y R .E Et I MJ A n. Mm M advantageously. r

might produce fading n '1,922,116 ANTENNA ARRAY I John Stone Stone, San Diego, Calif., assignor to American Telephone and Telegraph Company, aCorporation of New York Application vAprilY 12,

The principal object of: my invention is to provide a new and improved system of antennas for receivingradio waves (or transmitting them) Still another object of my invention is to provide an array of antennas adaptedv to compensate one another Aand receive as a whole in a manner to obviate fading and'other drawbacks. Still another object of my invention is toprovide an antenna fan vl0" for lreceiving that shall give `a substantially'uniform response. notwithstanding conditions that for a single receiving antenna.. ,All Vthese objects and other objects A `of my invention will become apparent on consideration of a limited number of specific examples of -practice according to the invention,

` tenna andtwo wave which will here be presented by way of example with the understandingA that the scope of the invention lwill be indicated in the appended 'claims VVReferring to thedrawings, Fig. 1 is a diagrammatic elevation showing an inclined antrains i'n different direc- Y .1 tions in relaticnthereto. Fig. 2 is a curve diagram showing intensities of response for the antenna of Fig. 1 at different angles of inclinabetween the waves in. 3 is an enlargement of Fig.v 2. Figs. 4 and 5 are diagrammatic eledifferent phase ldifferences the two wave trains. Fig. of the left-hand portion tion thereof, and for .vations of antenna -rays or fans at uniform indicating how the antennas are i ponents of angular spacing and of uniform length. l Fig. 6

a similar diagram except that the spacing.

is non-uniform. Fig. 7 has uniform spacing, but here the antennas are graded in length. Fig.

8 has non-uniform spacing and the antennas Fig. 9 is aY diagram to be connected to the common receiving instrument. Fig. 10 Ais another diagrammatic elevation similar to'Fig. 1i `in.,vvhch-wave `trains approach at equal anareof graded lengths.

i Ygles,. to the horizontal;

It is a commonly accepted theory for the fading of signals in long vdistance short wave radio transmission that it is due tov interference at the receiver between two or more comthe radiation from the transmitter which reach the receiver at different` varying anglesof incidence relatively to the'horizontal in the vertical plane that contains 1the transand that these varying phase relations. Such interference phenomena give rise to a shifting interference pat-y antenna,

1930. seriaiNo. 443,832 7 claims. (o1. 25o- 33) will give an introductory consideration of the *v effect of two wave trains liquely on a single antenna. The principlethat will be established in this connection will be applicable in connection with the antenna ar-l rays of my invention. i

Referring to 4Figure l, AB is an antenna, not grounded, inclined'at an angle 6 to the vertical. It is assumed that from the transmitting station which lies' in the'vertical plane containing AB, two wave trains `come tionsy indicated by the arrows y1 and 2, making the respective angles with the horizontal 01 and H2. It will be assumed in this discussion that the two wave trains indicated by the arrows` l down `in the direc- IV and 2 are of equal intensity Vand differ in phase 75 In theforegoing equation Z is the length of 8 the antenna AB, H is a constant dependent'v upon'the intensity of the received waves at `the c is the velocityof light and wt is kthe usual independent variable corresponding to the flow of time and tothe .frequency of the received waves. Y i Y A study of Fig. 1 in connection with theforegoing equation leads readily Ato the inference that even in the extreme case of a complete interference'between the wave trains,` the an- 95 tenna will still respond unlessthe wave trains coincide in the direction'of theirmotion, which is a condition excluded by hypothesis in the present discussion, or unless the antenna is perpendicular to the line which bisects the angle between ythe lines of direction of the wave trains. In this case of complete interference of the wavetrains, the-maximum response ofthe antenna will be realized when it .bisects the angle between the directions of the vwave trains.

I have made afstudy of the effect of varying the parameters in the foregoing equation, andV a few illustrative diagrams of my results will now be presented.` Fig. 2 is a curve diagram 11.0

showing the amplitude of response fas alf'unction of 6 according to the foregoingV equatioinasv a function of 0 for several diierent Avalues of il.

-In otherv words, Fig. 2shows the intensity of: response for various inclinations of the antenna- 0:15 degrees, :i 3hatis,` one wave trainy comes'jin horizontally andthe other cornes downward at thecondition of opposition (50,:90 degreesfthe. more nearly must the antenna approach .thev angle of 7.5" degrees to the horizontal if itsmaX'- imurnY response is to be secured. words, this is the optimumv angle'for the ariff Y tenna to getrthe best effectif.' there an angle o f 15V degrees to the horizontal. f The curves of Fig. 2 .show that asthe 'phases of the waves of the two wave trains approach Inf' other is'Y serious .int.'erference' Y between the received wavesV "Figs.. '2jY and i: directions of the Waves,-thatis, other values for vFor greater jclearness, theportion of Fig.' 2`at the left' has been 'replotted' onga largenscaleeinj Fig. `3..

'By .continuing the .study lile that shown 5in', V3, but vwithother angles ,f for .the

f 61 and 02, ndthat in general the direction, of

l of antennas all lyingfin they varra,y.or fan and tend over a span 0 f `;24deg re es; .that is; .thefirsti studied had 7l antennas, wliosesnsn 15.8 dfi-Q; `grees. -v 5532 1 comparing the the f anvof Fig;a 5 withhat ber of antennafper unitvangleandth l plan exemplifiedin Fig. v6,.. whic 7011 tennas l p'rogltssivelyA `greater i, v vith.` depariilll? `and appearing inelevationas Y Taking the arithmeticalsum of 'there-V Vsponses in the `individual .antennas of i Such an .adding them@ nn@ that.. there. obtained a practically constant aggregate freff] V spense for all-values ofi/f, the phasediierence.; antennasV changez-.inu position by fend .5.

In one case; the

, 7.011.@ @t Zero.; ai'iayjsat.' 24 degrees. The foregoing statement,

about Vthe uniformity of response is true.when

the antenna or .best response to lin terfering `waves is such that itglies lsquareacress the bisector oflthe'fanglegmade by the directions ofj those Waves, inotherwords,(0;-{502)/2. v

yI Vtry a pluralityf, rticai piane com- 1 receiving Stations.'

Going on with thisstudy,A

thedirections vof Ythe'two Wave trains aregre;

spectivelyti() 'degrees' vand. 02:15 degreesiflikef wise; when-01:9 degrees and (22'i24degrees. ''Y

. Again., similar' results are obtained, .with an antenna fan more likeFig4-5 ascornpared` \7v '1i ;li n

wave train A directions 'are of: Fig. 4, we .see thatmg. 5 has msstptmspan and 1nore-of antennasper Yunit Sangle 'Y in the This change in Vthe Y proportions of the fancorrespond s. to a*'1ed11 ction of the' angle 1+02fbetween the, incidenlabeamf. 3%??- ation. Thisillustrates the grepen[rell betweenthev angular spans Yof the fans.

divergence between theincident beanis o ation; j f

ence yof. ,certain of these factors.'-

h fcon'sistsf in makingV the angular spacing.betweenthejanf from the horizontal.v

antennas .in .their distriliution.

theantennas-as shown invFig. 'L so astogetvtlie The Voutputsgfronf'i` thervr respective antennas message `the horizmrwmch. are graded in. raggiunge, impedir/ radiefrequency-debectrsfjfor saidsm frequency .to audio same result' as Fig.Y 6. Again.. asin Fig; 8, Il may varyboth .the angular density and the length :of thev individual antennas.

should rst be reduced from VLradio frequency to audio frequencyand then combinedqto thef'com- Forthe wave trains coming Vdown 'tov the re. ceiving .station at an angle to the horizontal, there will, of course, -`be vmore or less :reection rom f the earths surface'..in`the "'=immediate neighborhood. o kmake this reflection elect constant, "and thereforepredicable, an yextensive wiremeshindicated at M in Fig. 9 should be laid Vover the groundjaroundand beneath'the i antenna array. f A study ofthe-case when am;V '611 v ...may be. takenasiarsp'ecial case of Fig. 1in the15-" `foregoing equation havior .ofthe 'antenna :fans of Figs. v425, YK6.21 and 8 is fsubstantiallyglfas jalready- 'explainedwhen dueallowance is mad rfor'reiection.iog'fthe up to';1 ts-rnainiurn'value Y' ground Y' yIvclaiin.: .y 1". An antenna array lconsisting Vofa. plurality of ungrounded linear vl'zlrntennasY VallV parallelv with a single verticalfplane; and respectivelyfat vii.-` rio'usanglesto tliehorizo'ntal which alr graded in their magnitudes 'l with regularly incresig'- intervals f 1 '..i

are glfdedin'their magnitudes 3'. Anantenna arr c'vis'.gantsnheerey i0 Obvitfad stngloif.v antennas at'j Avarious @angles to* :the desired rectio'nfkif/reception; and ''e'alns tQ'adlV the .effects in these antrI- j nas 1n a yeo dion receiver whereby a null "etl'ect- .incei'tainj'QLQthe antennas will' 'be compensated bya reinforcing ei'fe'ct in"`o th`ers 15- 6. An antennaarrayconsisting of'a."plurality of A"iingrounded linear antennas allp'arallel to; fa.. single vertical plane and atrespectiv'e 'angle'sto receptioiwhiohconsistsj'in applying thefref;Y ceivd f space'A waves .to developfwire.. waves: inV` di rectionsf' ga'tlV various 1 angleslto the` receivelf waye fronti-"said idi'rections all v4lying .parallel ,with theYY1 -comnion \`f er,t'ica1 .-r plane .i o fjthetransxnittingf receiving stationsrdetecting said ,Ifesective wire waves 2me rducin'gtheir frequencies .fromrdlQ freszunyf and. @whining the antiimemfca1-1y.: f

audio frequency Vand' it'fyshows that'.thebe-Vv 

